News (handpicked)

Israeli tanks have pushed deep into Gaza City, prompting fierce exchanges of gunfire with fighters of the Palestinian militant group Hamas. The UN's relief agency, Unrwa, says part of its HQ in the city is on fire after being shelled by the Israelis. Secretary General Ban Ki-Moon expressed outrage at the attack, and said Israel had told him it was a grave mistake. Efforts to reach a truce continue, with Israel's head negotiator due in Cairo to discuss an Egyptian ceasefire plan.

Hamas said the talks had made progress, but did not elaborate. Speaking to reporters on the Israel-Gaza border, Unrwa spokesman Christopher Gunness said three of the agency's employees were hurt in the attack.

He said the compound was hit by what Unrwa believed to be three white phosphorus shells, which are incendiary weapons used as a smoke screen. About 700 people were still in the compound, he said, and he was particularly concerned about the proximity of the fire to five fully loaded fuel tanks.

Asked whether he was sure the attack had been carried out by Israel, he said he was not aware of Hamas having access to white phosphorus. Mr Gunness added that Unrwa would not be able to distribute food or medical supplies on Thursday as its trucks have been unable to leave the compound.

Escalation

Israeli military officials say they attacked 70 military targets overnight, including a mosque they say was being used to store weapons.

The BBC's Hamada Abu Qammar in Gaza says the coastal enclave has come under extremely heavy artillery fire from the east, and the skies are full of thick smoke.

He said Israeli tanks seemed to be pushing closer to the heart of Gaza City, close to the UN headquarters, and that there were reports of 21 people killed in fighting since the early hours.

Rushdi Abu Alouf, the BBC's Gaza producer, says the building where he lives in Tel al-Hawa, south-west of Gaza City, has been surrounded by Israeli tanks.

"People have been screaming from their balconies, calling for help," he says.

He says that from his window he can see fighters from Hamas and other Palestinian factions firing at Israeli tanks from rooftops and balconies, and that the Israeli tanks have been firing back.

Tank shells have hit the lower floors two or three times.

Reports say at least 15 rockets were fired from Gaza into Israel since the early morning.

More than 1,000 Gazans and 13 Israelis have reportedly died so far in the conflict.

In other developments:

UN Secretary General Ban Ki-moon is meeting regional leaders as part of intensive diplomatic efforts to end the fighting

A tower block in Gaza City that houses the offices of the Reuters news agency and several other organisations is hit by an explosion, injuring a journalist for the Abu Dhabi television channel

A boat carrying medical supplies to Gaza is surrounded by Israeli warships in international waters off Lebanon's southern coast and forced to return to Cyprus, according to charity Free Gaza

Palestinian deaths in the Gaza Strip reach 1,028 according to Gaza medical sources. Nearly a third of the dead are said to be children.

'Detailed vision'

Israel's chief negotiator Amos Gilad has arrived in Cairo to discuss an Egyptian ceasefire plan that could end the 20-day-old conflict.

Egypt has been leading efforts to broker a ceasefire that could include a peacekeeping force being deployed along its border with Gaza to prevent the smuggling of weapons.

Hamas official Salah al-Bardawil said his movement had presented a "detailed vision" of how to bring about a ceasefire to Egyptian negotiators.

These details concerned how to ensure border crossings into Gaza could be re-opened under international supervision, he said, and would be presented to Israeli envoys visiting Cairo.

Hamas, which controls Gaza, has said any ceasefire agreement would have to include a halt to Israeli attacks, the complete withdrawal of Israeli forces and the opening of border crossings to end the blockade of Gaza.

Israel has said it will not agree to a deal that does not guarantee an end to Hamas's smuggling of weapons across the Egyptian border and the cessation of rocket attacks into southern Israel, our analyst adds.

However, Israeli government spokesman Mark Regev said there was "momentum" to the talks.

"Ultimately we want to see a long-term sustainable quiet in the south, a quiet that's going to be based on the total absence of all hostile fire from Gaza into Israel, and an internationally supported mechanism that will prevent Hamas from rearming," Mark Regev said.

Egypt and other key Arab players can do some coaxing and arm-twisting with Hamas, says BBC Arab affairs analyst Magdi Abdelhadi, but there is little pressure they can bring to bear upon Israel: only the US has that sort of influence.

Fuelling extremism

Israel launched its offensive on the coastal enclave on 27 December and has refused to allow international journalists to enter Gaza, making it impossible to independently confirm casualty figures.

The offensive has provoked widespread international condemnation at the cost in civilian casualties and the ongoing humanitarian crisis in the coastal enclave.

A BBC correspondent in Egypt who saw children with gunshot wounds said he had been given detailed accounts by Palestinian civilians of how they and their children had been fired at by Israeli soldiers.

An Israeli army spokeswoman said Israel did not deliberately target civilians.

"We don't shoot innocent people, not underhand, not deliberately," Major Avital Leibovich told the BBC. "We only shoot when there is a life-and-death situation or when there is fire opening at us."